| Abstract: | The sulfhydryl reagent p-chloromercuribenzene sulfonate increased the ISC across substrate-replete toad urinary bladder when applied to the mucosal (apical) surface. This increase was accounted for by an increased mucosal to serosal net flux of Na+. In the absence of substrate, the rise in ISC was accompanied by an irreversible increase in tissue conductance which was not apparent in the replete preparation. These findings suggest that p-chloromercuribenzene sulfonate may be useful in marking mucosal functions associated with the Na+ transport apparatus. |
